The Serious Fraud Office is pursuing criminal charges against four people in relation to donations paid into a National Party bank account, but their identity is likely to remain secret for some time.
The National Party says neither the leader Simon Bridges, nor the party, are among those charged.
The agency launched an investigation in March last year after the police referred on a complaint by former National MP Jami-Lee Ross.
RNZ political editor Jane Patterson, speaks to Susie Ferguson.